thanks for the links -- although I think some of the people in Millionaire Next Door skirt closer to what OP was referring to -- people who never spend money, not to retire early or do something interesting with their money, but just to hoard it.

I have known a few people who I considered pathological savers -- people who, like the fictional Scrooge, seem to save for the sake of saving, and do not ever enjoy the wealth they have created, nor do they turn it to a useful purpose in the world via large charitable donations. This is very rare in my experience, however. The only people i have known like this are in the generation that grew up during or shortly after the Great Depression.